Thread insert



April 13, 1948. H.J. l--INDLlsv/y 2,439,685

v 'ranma INSERT l Filed Sept. 30, 1943 By Y 75;@ iaMay/q am@ Hr roe/vera Patented Apr. 13, 1948 OFFICE THREAD INSERT vHoward J. Finales. shaker or to Eaton Manufacturing Heights; Ohio, asaign- Company, Cleve-- land, Ohio, a corporation of Ohio Application September 30, 1943, Serial No. 594,393

" 6' claims. (ci. ss-szi This invention relates to threaded inserts of, the kind made from helically wound wire and aims to provide an improved construction for such inserts.

In my earlier application Serial No.. 498,493, led August 13, 1943, now 4Patent No. 2,363,662

through the same insert and showing the same in a partially completed state.l

granted' November 28, 1944, I have disclosed a threaded insert (formed from helically wound wire of a cross-sectional shape such that the edges of the wire form the internal and external threads of the insert. In the insert referred to the internal and external threads are necessarily of the same pitch which limits the range of usefulness of the insert to some extent and moreover this form of insert does not readily permit the use of the relatively coarser threads which are desirable for obtaining increased holding power where the inserts are used in relatively soft materials.

The present invention seeks to overcome these disadvantages and, as one of its objects, aims t provide a novel insert of the character mentioned which has an extended range of application and use by reason of the fact that the inner and outer threads can be of diiierent pitches.

Another object of my invention is to provide an improved form of wound wire insert having a wide range of applicationand which permits the use of relatively coarser threads for obtaining increased holding power when the inserts are to be used in relatively soft materials.

Yet another object of my invention is to provide a novel insert construction and method in which the insert is formed of helically wound' iiat wire and a thread or threads are cut in one or both surfaces of the insert.

The invention also aims to provide a novel insert in which the adjacent convolutions are brazed together prior to the cutting of the thread `or threads thereon.

Still another object of this invention is to provide a novel insert construction in which the flat Wire for the insert has a tapered projection along one edge which forms a helical thread on the insert and a nat face along the other edge which forms a cylindrical surface for the cut thread.

The invention may be further briefly summarized as consisting in certain novel forms oi construction hereinafter describedv and particularly set out in the appended claims.. v

In the accompanying sheet oi' drawings:

Fig. 1 is a longitudinal sectional view taken through a threaded connection using one form if my novel insert.

Fig. 2 is a longitudinal sectional view taken Fig. 3 is a longitudinal sectional view taken through another threaded insert constructed according to my invention.

Fig. 4 is a longitudinal sectional view taken through the insert of F18. 3 and showing the same in a partially completed state. l

Fig. 5 is a longitudinalsectional view taken through still another form of my novel insert; and

Fig, 6 is a longitudinal sectional view showing the insert of Fig. 5 prior to the cutting of the threads thereon.

In proceeding with a more detailed description ol'v my inventionI will refer iirst to Fig. 1 which shows my novel insert Ill being used in forming a threaded connection between the member II and the body I2. The member II is here shown as being a screw having a stem I3 provided with a standard thread I I such as a 1/20 thread. The body I2 may be a body or part formed of relatively soft material such as wood, aluminum or the like in which it is desirable to use the insert I0 as an adapter or for the purpose` of obtaining a stronger connection for the screw I I. The body I2v has an internally threaded opening I2a into which the insert I0 is screwed.

The insert I0 comprises a bushing or sleeve formed by a helically wound nat wire or strip I5 and having helical internal and 'external threads I8 and II. The internal thread I6 is of a contour and pitch to receive the threaded stem I3 and is obtained as the result of the winding of the wire I 5 to helical form. 'Ihe external thread I1 is cut on the outer surface of the bushing by a suitable die. The thread I'I here shown is a 1/2"13 thread which is relatively coarse as compared `with the internal thread I6 and affords a relatively strong connection when the insert is screwed into the correspondingly threaded opening I2a of the body I2.

In Fig. 2 I show the insert l 0 in a partially completed state in which the wire I5 has been Wound to helical form, but in which the external thread Il has not yet been cut on the external surface of the insert; As shown in Fig. 2 the Wire JI5 is a flat wire `or strip having substantially dat top and bottom faces I8 and. when the wire is closely wound to helical form, the faces I8 of adjacent convolutions are in contiguous relation to each other. One edge of the wirehas a tapered proj ection I9 extending therealong andthe opposite edge of the wire has a substantially fiat face 20 extending therealong. When the wire is wound to helical form, as Just explained, the tapered I3 forms the internal helical thread I6 andtheiiatfacenformsanexternalcy drical surface on which theexternal thread I1 is cut. Thewlreusedinformingtheinsertis of such thickness that the tapered projection I! thereon will produce the thread i3 having the desired pitch and vthread contour. The `wire used in forming the insert can be o'f any desired width depending upon the size of opening in which it is to be used in the body|2 and the size of the threaded member to be screwed into the insert.

Since the external thread I1 is relatively coarser than the internal thread I3, it will be observed that its pitch does not correspond with the pitch of the helical convolutions of the wire and that the thread |1 extends across the meeting line of the faces I3 of the adjacent wire convolutions. The cut thread I1 can be formed on the insert by the use of any suitable threading die or threading operation. For strengthening the insertfand preventing spreading of its convolutions during the cutting of the thread l1, or during its subsequent -handling and use, the adjacent convolutions are joined together by brazing or the likewhich is indicated at 2|.

In Figs. 3 and 4 of the drawings. I have shown an insert 22 similar to the insert` III but in which the internal thread-23 is a cut thread and the external thread 24 is obtained on the insert as the result of the helical winding of the flat wire 25. Fig. 4 shows the insert partially completed. that is to say. in the condition obtained by the helical winding of the flat wire 25 and priorto the tapping of the opening 23 to .provide kthe internal thread 23 therein.

The .fiat wire 25 used in forming the insert 22 has a tapered projection `21 along one edge thereof and a substantially flat face 23 along the opposite edge. The wire is wound so that the projection 21forms the external thread 24 and the hat face 28 denes the cylindrical opening 26. The wire 25 is of such thickness and width, that the thread 21 will be a relatively coarse thread of the desired pitch and contour and such that the desired diameters will be obtained for the thread 21 and the opening 26.

The internal thread 23 can be formed in the opening 26 by the use of any suitable tap or threading operation. The convolutions of the insert 22 are also joined together by brazing or the likeshown at 25a. It will be noted that since the internal thread 23 is a relativelyner thread than the external thread 21, its pitch is less than the pitch of the wire convolutions and extends across the meeting line of the at faces 29 of the adjacent wire convolutions.

projection 31 extending therealong and when the wire has 'v been wound into bushing form these fiat faces cutting of th'e threads 32 and 33 thereon the ad- In Figs. 5 and 6 I have shown still another insert 30 which is also Vformed from helically wound fiat wire 3| but which has both its external and internal threads 32 and 33 cut thereon. .The insert 3|!y also has its adjacent convolutions connected together as by mean's of brazing, or the like, indicated at 33.

Fig. 6 shows the insert 30 in its partially completed state, that is to say at the stage in which the wire 3| has been wound to helical form and the adjacent 4convolutions have been brazed together, but prior to the cutting of the external and internal threads 32 and 33 thereon. The Wire 3| used in making this insert is of substantially rectangular cross-section having flat top and bottom faces which provide co-extensive surfaces 35 on the adjacent convolutions when the wire has been helically wound. The edges of the wire have substantially flat faces 36 and tion and use than similar understood, of course,

jacent convolutions will be held against spreading during the threading operation. Buch brazing also results in a stronger insert being formed and enables the insert to be embodied in a threaded connection without becoming c twisted or distorted. The brazing can be carried out by the use of any suitable operation or apparatus and in all cases the brazing becomes a permanent part of the insert.

From the foregoing description and the accompanying drawing it will now be readily understood that I have provided a novel form of threaded insert having a wider range oi' applicainserts heretofore proposed, and which also make possible the use of a relatively coarser thread on the outside-of the insert which is desirable in obtaining a stronger connection when the insert is used in a body of relatively soft material. t

While I have illustrated and described my novel threaded insert in more or less detail. it will be that I do not wish to be correspondingly limited but regard my invention as including all changes and modifications coming within the spirit of the invention and the scope of the appended claims.

Having thus described my invention, I claim:

1. An insert of the character described, comprising a bushing formed merely of helically wound flat wire and having adjacent convolutions brazed together and also having a helical thread .cut in at least one surface thereof, the pitch oi' the thread being different than the pitch of the helically wound wire.

` 2. An insert of the character described, comprising a bushing vformed merely of a helically wound rectangular wire and having adjacent convolutions brazed together and also having a thread cut in at least one surface thereof.

3. An insert of the character described, comprising merely wire helically wound to bushing form and with adjacent convolutions brazed together, said insert having a cut thread in at least one surface thereof.

4. An insert of the character described, comprising merely helically wound flat wire having a tapered projection along one edge which forms a helical thread on the insert, the adjacent convolutions of said wire being brazed together and said wire initially having a flat face along its opposite edge. and a thread cut in the surface formed by said fiat face of the wire.

5. An insert of the character described, comprising merely a bushing formed of helically wound wire initially rectangular in shape, adjacent convolutions of the bushing being brazed together, and cut threads of different pitches on the inner and outer surfaces of the bushing.

6. An insert of the character described, comprising merely helically wound flat wire having a tapered projection along one edge which forms a helical thread on the insert, the adjacent convolutions of said wire being brazed t0- HOWARD J .l FINDLEY.4 REFERENCES CITED The following references are of rec'ord 1n the nle of this patent:

Number 6 f UNITED STATES PATENTS Name f Date Gare v June 9, 1896 Barnes Aug. 6, v1940 Caminez Nov.. 11, 1941 Wagner Novi. 17, 1942 Hoopes Dec. 29, 1942 FOREIGN PATENTS Country Date M Number Austria June 3, 1943 

